Lawrence Livermore Nuclear Labs just declassified a whole bunch of old atmospheric nuke test films and put them on youtube. There's a full list to view, so here's the link below. Some of these are spectacular visions of Hell, some in black and white, some in color. The last one, #64 - Operation Teapot - Turk 28112, is really cool. It's a slo-mo of a nuclear fireball covered with exploding pimples hitting the ground.

If you'd been there, you would've probably been a some grunt soldier, sent in a couple of hours after the test as part of, and I quote: training and "indoctrination" about atomic warfare. In other words, test subjects.